Toshiba MMU-AP0152SH Service Manual page 78

(*3) Check for solenoid valve of outdoor unit (For multiple outdoor unit system)
a) Clogging check for SV3A valve
• While outdoor unit is operating, set up SW01/02/03 = [2] [1] [3] to 7-segment display [Hr] [ 2], and push SW04
for 2 seconds or more.
• Set up SW02 = [4], and turn on SV3A valve. (7-segment display [Hr] [ 3A])
• If temperature is low at secondary side of the valve or it does not change, clogging of valve or check valve is
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considered. ( in the figure.)
b) Leakage check for SV3C valve
• While outdoor unit is operating, set up SW01/02/03 = [2] [1] [3] to 7-segment display [Hr] [ 2], and push SW04
for 2 seconds or more.
• Set up SW02 = [6], and turn on SV3C valve. (7-segment display [Hr] [ 3C])
• If temperature does not change (up), clogging of valve or strainer is considered. (
(*4)
a) Clogging check for oil-equalization circuit
• Drive the outdoor unit. (Drive both compressors in the unit.)
• After driving for 10 minutes, check temperature of TK1 and TK2 sensors and temperature of oil-equalization
‡
circuit capillary ( in the figure) were raised.
(Criterion)
TK1, TK2=Td1, Td2 temperature – Approx. 10 to 30°C
Oil-equalization capillary tubes should be higher sufficiently than outside air temperature and suction temperature.
• If temperature is low, a malfunction of capillary, strainer, or check valve is considered.
Repair the defective parts.
High-pressure
sensor
5
Check joint
separator
(SV3D)
Solenoid valve
(SV41)
6
High-pressure
SW
(TD1)
Sensor
(TK3)
Strainer
(TK1)
(TK4)
(SV3E)
4
7
1
Strainer
Balance pipe
Packed valve
‚
in the figure.)
(SV2)
Oil
Solenoid valve
(SV42)
High-pressure
SW
Sensor
(TD2)
2
Strainer
(TK2)
Oil tank
7
(SV3A)
Solenoid
valve
(SV3B)
Check
valve
3
Check code name Check code name
[H08] / [d4] Oil level detective
temperature sensor error
(d07 / AI-NET)
Sub-code: 01: TK1 sensor error 02: TK2 sensor error 03: TK3 sensor error 04: TK4 sensor error
The detected error is an oil level detective temperature sensor error.
Check disconnection of the wiring and resistance value of the sensor.
If the sensors are normal, replace the outdoor I/F P .C. board.
Check code name Check code name
[H16] / [d7] TK1 temperature detective circuit error
(Sub-code: 01)
(d07 / AI-NET)
YES
Is not TK1 sensor detached?
NO
YES
Is there no miscabling or misinstallation
on TK1/TK2/TK3/TK4 sensors?
* Characteristics-4
NO
NO
Are characteristics of TK1 sensor
resistance value normal?
* Outdoor unit temp sensor characteristics-4
YES
Start a test operation in COOL or HEAT mode.
TK1 sensor temp is displayed on 7-segment display with SW01/02/03=[1] [11] [2].
Check TK1 sensor temp approx. 10 minutes after compressor 1 has operated.
If low temperature continues (approximately outside temp) or temperature
does not almost change, a clogging of strainer of oil-equalization circuit,
clogging of capillary tube, or malfunction of check valve is considered.
No error
Error
Check the clogging of SV3E valve.
(Note 1)
(Note 1) Refer to item [H07] error.
No error
Check I/F P.C. board
Cause of operation
TK1 to TK4 sensor Open/Short
Circuit Connector
TK1 CN514 (Black)
TK2 CN515 (Green)
TK3 CN516 (Red)
TK4 CN523 (Yellow)
Cause of operation
1. Coming-off of TK1 sensor, miscabling,
characteristics error of resistance value
2. Oil-equalization circuit error
(Check valve, capillary clogging,
strainer clogging)
3. Refrigerant stagnation in case of
compressor shell
Correct installation of sensor.
Correct miscabling/misinstallation.
TK1: CN514
( )
TK2: CN515
TK3: CN516
TK4: CN523
Sensor error
Error
Replace clogged part.
Compressor 1
Strainer
Capillary tube
TK1
Oil tank
Replace SV3E valve.